In A More Flexible Workflow Dennis Kardys describes an all-too-familiar design process problem in agencies:

In theory the design assembly line made us extremely efficient. Design documents were handed off like batons from one team member to the next as projects moved through stages. The reality however, is that projects would often get held up as clients mulled over wireframes or fought for consensus within their organization. […] In a nutshell, there was too much talking and too little testing.

Dennis goes on to describe how they’ve successfully changed their workflow to incorporate interactive prototypes and frequent customer feedback. These aren’t new ideas, of course, but it’s great to see it from an agency perspective, where these flexible workflows can be much harder to implement.

Sticking with the design process theme, Tuhin Kumar wrote a good post about matching the type of critique a project requires to the design phase that project is currently in. From Feedback & Fidelity in Design:

Momentum is one of the best things for any product design process. It helps you from straying around the wrong path, or losing your core vision, or trying to solve too many things in the first release. […] Asking the wrong questions at the wrong fidelity or giving the wrong feedback kills momentum like nothing else.

Tuhin defines some different phases of the design process, and recommends the right questions to ask during each. Both these articles give some great tips to improve your design workflow.